Safety-anchored multi-conductor water-cooled electric arc furnace cable

ABSTRACT

The ends of the individual conductor cable ropes of this multiconductor water-cooled electric arc furnace cable are secured within the cup or pocket of the terminal by embedding them in solder. In order to prevent the individual conductor cable ropes from dropping out of the terminal pocket or cup when a clogging or other failure of the water cooling system causes the cable to overheat and consequently melt the solder, two of the individual conductor cables are additionally secured to the bottom wall of the terminal cup or pocket by being encased in an L-shaped tubular conductor clamp. The transverse arm of each such clamp, and the cable rope end therein are drilled for the reception of the shank of a threaded fastener, such as a bolt, the shank of which passes through a bore in the bottom or end wall of the terminal cup and receives a threaded nut on the exterior thereof.

United States Patent 1191 Goodman SAFETY-ANCHORED MULTl-CONDUCTOR WATER-COOLED ELECTRIC ARC FURNACE CABLE [76] Inventor: Daniel J. Goodman, 23236 Westbury Dr., Saint Clair Shores, Mich. 48080 Notice: The portion of the term of this patent subsequent to Mar. 28, 1989, has been disclaimed.

[22] Filed: Sept. 15, 1972 [21] Appl. N0.: 289,260

[52] US. Cl 174/15 C, 174/19, 219/130, 7 339/117 [51] Int. Cl. 1101b 7/34 [58] Field of Search 174/15 C, 19, 20, 47, 21, 174/74; 13/15, 16, 32; 339/117, 112; 219/130 [56] References Cited UNITED STATES PATENTS 3,652,797 3/1972 Goodman 174/15 C 3,604,831 9/1971 Goodman... 174/15 C 3,601,520 8/1971 Carasso 1 174/15 C 3,456,064 7/1969 Toto 174/15 C 1451 *Apr. 2, 1974 Leathers 174/15 C 3,163,704 12/1964 3,340,346 9/1967 T0tO.-....- 174/15 C 3,065,290 11/1962 Grove 174/15 c Primary Examinr-Bemard A. Gilheany Assistant Examiner-A. T. Grimley [5 7] ABSTRACT The ends of the individual conductor cable ropes of this multi-conductor water-cooled electric arc furnace cable are secured within the cup or pocket of the terminal by embedding them in solder. In order to prevent the individual conductor cable ropes from dropping out of the terminal pocket or cup when a clogging or other failure of the water cooling system causes the cable to overheat andconsequently melt the solder, two of the individual conductor cables are' 6 Claims ,.4 Drawing Figures m G 64 w a I O @3 o o a O O r a g a 1 sAFETX-ANononEp U ncoNnucToR WATER-COOLED ELECTRIC ARC FURNACE ABLE In the drawing, FIG. 1 is aside elevation, partly in central longitudinal section, of one end .of a multi-conductor water- .cooled electric arc furnace cable, showing the safety anchorage construction, according to one form of the present invention;

FIG. 2 is a cross-section through the cable beyond theterminal, taken-along the line 22 .in FIG. .1;

FIG. 3 is a left-hand ,endielevation of the cable shown in FIG. 1; and

FIG. 4 is a fragmentary bottom plan view of'one of the cable anchoring devices and its threaded anchoring fastener, with the Conductor-securing solder vand the terminal omitted,'loo king in the vdirectionof the arrows 44 in FIG. 1.

Referring to the drawing in detail, FIG. 1 shows a safety-anchored multi-co nductor water-cooled electric arc furnacecable, generally designated 10, for electrically connecting a conventional transformer (not cables is employed with each furnace. As the primary voltage of such a transformer is in the neighborhood of 13,000 volts and the secondary output a current'of 10,000 amperes per phase at 230 to 800 volts, the

breakageof such a cable is extremely dangerous to nearby workmen, and it is such breakage that it is the purpose of the present invention to prevent.

In particular, the cable 10, ofwhich only the furnace connection end 12 is shown, consists of a forward terminal l4 and a multi-conductor water-cooled cableunit 16 secured thereto and safety-anchored in a manner described below. The forward terminal 14 is constructed of heavy copper and has a forward connection blade 18 adapted to-be connected to the furnace. The rearward terminal (not shown) at the opposite end of the cable unit 16 is of similar construction and is connected to the transformer (not shown). The forward connection blade 18 has flat opposite sides 20 (FIG. 3) and contains multiple spaced holes 22 for the reception ofbolts (notshown) by which it is secured to the furnace or transformer, as the case may be. The blade 18 at its forward end 24 is provided with a threaded port 26 leading to the forward end of a cooling water pas- 'sageway 28, the opposite end of which terminates in a rearward or inner port 30 opening into thecavity or cup 32 of the rearward portion or base 34 of the terminal 14. t

The rearward portion or base 34 of the terminal 14 is of hollow cylindrical shape and has an outer generally cylindrical surface 36 provided with annular frustoconical ratchet teeth 38 which engage and penetrate the inner surface 40 of a hose 42 of synthetic rubber such as that knowncommercially by the trade name Neoprene. The forward end of the hose 42 is secured to the terminal 14 by multiple longitudinally-spaced hose clamps 44 which cause the annular ratchet teeth 38 to indent and tightly gripthe hose 42 in a water-tight interlocking connection.

The rearwardportion or base 34 adjacent the inner or rearward port 30 is provided with a bore 46 which in turn opens into a counterbore 48 from which it is separated by an annular shoulder 50 extending therebetween and forming the bottom surface of the bottom wall or end wall 52 of the terminal base 34. Seated in the :bore 46 is the outer or forward end of ariser tube 54 which is preferably of copper, the inner or rearward end of which is seated in and snugly engages the cylin- 'drical inner surface 56 of a fluted perforated core tube 58. The core tube 58 is of elastic deformable material,

such as rubber or synthetic rubber, and has multiple perforations 60 therethrough for the flow of cooling water reaching them from the port 26 by way of the passageway 28, port 30, riser tube 54 and core tube :58. The fluted outer surface 62 of the .core tube 58 is engaged by the perforated tubular jackets64 of a plurality, of .cable conductor ropes 66, so-called because they are composed of hair-like fine copper wires braided into a form resembling a hemp or manila rope. The perforations 68 permit coolingwater to flow from the perforations 60 into the interiors vof the jackets 64 where the water passes along the spaces or interstices between the fine wires composing the cable ropes 66.

' The perforations 68 in each jacket 64 extend inwardly for a distance of approximately two feet and therebeyond each jacket 68 becomes imperforated. At this point, each jacket 64 is provided with a tubular plastic plug (not shown) held in place by suitable fasteners, such as by four brass screws.

The rearward terminal (not shown) of the cable 10 is similar to the forward terminal 14 except that its blade which corresponds to the blade 18 is disposed at right angles to the forward blade 18. The cable unit 16 together with its hose 16 and cable conductor ropes 66 as' well as the perforated jackets 64 and perforated fluted core tube 58 are conventional in construction and their details rearward, i.e. to the right of the section line 2-2 in FIG. 1, are beyond the scope of the present invention.

The outer end portion 70 of each of a plurality, preferably two,'of the individual cable conductor ropes 66 is encased in the longitudinaltubular arm portion 72 of an L-shaped tubular conductor clamp 74 and'extends through the transverse tubular arm 76. Both the transverse arm 76 and the conductor rope end 70 therein are drilled for the passage of the shank 78 of a threaded fastener 80, such as a bolt, having a head 82 abutting the transverse arm 76 which in turn abuts the annular shoulder 50 of the end wall 52 of the terminal 14. The shank 78 of the threaded fastener passes through a bore 84 in the end wall 52 and on its outer end is secured by means of a nut 86 threaded thereon.

The remaining conductor cables 66 are not so anchored, but, together with the anchored conductor cables 66, are secured within the counterbore 48 by a soft solder filling 88 which is poured into the counterbore 48 while it is in a molten condition and after the two anchored cable ropes 66 and their clamps 74 have been bolted into place. The cable ropes 66 are normally of circular cross-section (FIG. 2) but their forward 'portions 70 are passed through the tubular conductor clamps 74 while these are initially of circular crosssection. These are then swaged into rectangular crosssection after the cable rope end portions 70 have been inserted therein and the transverse tubular arms 76 thereof have been bent at right angles to the longitudinal tubular arm portion 72, whereupon the drilling of the bolt holes in the transversearms 76 and cable rope ends therein are carried out. Bolting is then performed by means of the threaded fasteners 80 to anchor the ends 70 of the anchored cable ropes 66 to the terminal 14, whereupon the remaining unanchored cable ends 70 are then inserted in the counterbore 48. This assembly is then placed in an upright position and the molten soft solder filling 88 is then poured into the terminal base or cup 34 so as to substantially fill the counterbore 48 and also the interior of the cable hose 42 substantially back to the ends of the perforated cable rope jacket 64. I

In the operation of the invention, the rearward cable terminal (not shown) of each cable is connected to the transformer, and the forward blade 18 of the forward terminal 14 is bolted to its connection at. the furnace. The port 26 is connected to its corresponding pipe at the furnace while the corresponding rearward terminal port is connected to a source of cooling water.

Consequently, during operation of thefurnace, the

heat generated by the flow of electric current through each cable 10 and also by the heat of the furnace itself is dissipated by the cooling water flowing through the perforated fluted'core 58 and thence around the jacketedcable conductor ropes 66 by way of the perforaanchored cable conductor ropes 66 now serve mechanically as safety supporting cables so as to prevent the remaining unanchored conductor cable ropes 66 from dropping out of the terminal cup 32. In this manner the .present invention prevents damage to the furnace by its otherwise falling against the furnace casing and also prevents injuries to adjacent workmen, either by the weight of the falling cable or by the tremendous electric current thus suddenly released, especially if water has fallen or is standing upon the floor of the furnace room.

I claim: 1. A safety-anchorage construction for the conductors of an electric arc furnace, said construction comprising a multiconductor electric cable having a hose with a set of electrical conductors of the same polarity encased therein and having a tubular liquid coolant conducting conduit extending through the center thereof,

an electric arc furnace connection terminal having a furnace connection portion at its forward end and having a cable conductor connection portion extending rearwardly from said furnace connection portion, said cable conductor connection portion having a hollow cylindrical side wall disposed within said hose in liquid-tight relationship therewith and also having an end wall with said walls defining a conductor-receiving cavity,

the forward end portions of said conductors being disposed within said cavity,

a heat-resistant mechanical conductor clamping device disposed in said cavity in engagement with the forward end portion of one of said conductors and securing said one conductor to said end wall of said cable conductor-connection portion in electrical conducting relationship therewith,

and a fusible electrically-conducting filler material also disposed in said cavity and electrically connecting said cable conductor end portions to said cable conductor connection portion.

2. A safety-anchored construction, according to claim l,.wherein said conductor clamping device.in-. cludes a tubular conductor clamp encasing the end portion of said one conductor and also includes means for securing said clamp and said end portion of said one conductor to said end wall of said terminal cup 3. A safety-anchored construction, according to claim 2, wherein said forward end portion of said one conductor and said conductor clamp have aligned holes therein, and wherein said clamp securing means passes through said holes into said end wall.

4. A safety-anchored construction, according to claim 2, wherein said tubular conductor clamp is'approximately L-shaped with a relatively long arm extending longitudinally of said terminal and with a shorter arm extending transversely of said terminal in abutting engagement with said end wall of said terminal cup. I

5. A safety-anchored construction, according to claim 2, wherein said clamp securing means includes a threaded fastener connecting said clamp to said terminal cup end wall.

6. A safety-anchored construction, according to claim 5, wherein said threaded fastener includes a bolt extending through said terminal cup end wall and also includes a threaded nut disposed externally of said end wall in threaded engagement with said threaded fastener. 

1. A safety-anchorage construction for the conductors of an electric arc furnace, said construction comprising a multiconductor electric cable having a hose with a set of electrical conductors of the same polarity encased therein and having a tubular liquid coolant conducting conduit extending through the center thereof, an electric arc furnace connection terminal having a furnace connection portion at its forward end and having a cable conductor connection portion extending rearwardly from said furnace connection portion, said cable conductor connection portion having a hollow cylindrical side wall disposed within said hose in liquidtight relationship therewith and also having an end wall with said walls defining a conductor-receiving cavity, the forward end portions of said conductors being disposed within said cavity, a heat-resistant mechanical conductor clamping device disposed in said cavity in engagement with the forward end portion of one of said conductors and securing said one conductor to said end wall of said cable conductor-connection portion in electrical conducting relationship therewith, and a fusible electrically-conducting filler mateRial also disposed in said cavity and electrically connecting said cable conductor end portions to said cable conductor connection portion.
 2. A safety-anchored construction, according to claim 1, wherein said conductor clamping device includes a tubular conductor clamp encasing the end portion of said one conductor and also includes means for securing said clamp and said end portion of said one conductor to said end wall of said terminal cup.
 3. A safety-anchored construction, according to claim 2, wherein said forward end portion of said one conductor and said conductor clamp have aligned holes therein, and wherein said clamp securing means passes through said holes into said end wall.
 4. A safety-anchored construction, according to claim 2, wherein said tubular conductor clamp is approximately L-shaped with a relatively long arm extending longitudinally of said terminal and with a shorter arm extending transversely of said terminal in abutting engagement with said end wall of said terminal cup.
 5. A safety-anchored construction, according to claim 2, wherein said clamp securing means includes a threaded fastener connecting said clamp to said terminal cup end wall.
 6. A safety-anchored construction, according to claim 5, wherein said threaded fastener includes a bolt extending through said terminal cup end wall and also includes a threaded nut disposed externally of said end wall in threaded engagement with said threaded fastener. 